Abstract: Provided are a suction apparatus for a fabric filter and a filtering device for liquid filtration using the same. A main suction slit and a sub-suction slit are provided in parallel by a partition. Thereby, pile threads undergo delayed straightening and fluctuation while going through the sub-suction slit and then are rapidly straightened in the main suction slit. Thus, a back-washing effect can be further improved.

Abstract: A backwashing suction device, a fabric filtering apparatus using the same, and a process of removing foreign materials attached to filter cloths of the disc-shaped filter pieces are disclosed. The backwashing suction device is separated from the disc-shaped filter pieces, thereby preventing the filter cloths of the disc-shaped filter pieces from being pressed down for a long time by the backwashing suction device. This is to improve the filtering efficiency of the filter cloths and to prolong a service life of the filter cloths. Further, a backwashing suction device is configured to be separated from disc-shaped filter pieces using a buoyant force, thereby providing a simple structure and a smooth operation. This is to enable close contact with or separation from the disc-shaped filter pieces, and a fabric filtering apparatus using the same.

Abstract: An improved process for producing an aromatic carboxylic acid from an aromatic alkyl hydrocarbon is described, wherein the improvement comprises using the same aromatic alkyl hydrocarbon as the azeotropic agent for separation of acetic acid and methyl acetate from water via azeotropic distillation. The process of this invention has considerable advantages over other known processes, particularly in regards to consumption of the azeotropic agent and utilities, formation of undesirable impurities and operating costs.